/*
 * Copyright 2009 Andy Lee.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package uk.co.optimisticpanda.gtest.dto.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * @param <K>
 *            Key
 * @param <V>
 *            list element types
 * @author Andy Lee A map of lists
 */
@SuppressWarnings("serial")
public class MapOfLists<K, V> extends HashMap<K, List<V>> {

	/**
	 * @param key
	 * @param value
	 *            an element to add to a list
	 */
	public void put(K key, V value) {
		List<V> list = get(key);
		if (list == null) {
			list = new ArrayList<V>();
		}
		list.add(value);
		put(key, list);
	}

}
